Pick the Right Camshaft Using

[@JohnGavagan-vi1or]

I am so amazed at David Vizard's knowledge and so grateful that he is willing to share it with the world. Those who give him a hard time should leave him alone and learn it the hard way. Of coarse that will be the expensive way too. It's hard to find good information on difficult subjects. Bad information witch seems to be in abundance can really steer you the wrong way. I can clearly see that David thinks at a higher level than most of us out here, and to share it with us makes him a very special person. Keep up the good work David! Thank you Andy for this video and believing in David.

[@jkbeaver4]

I've been reading his books for a decade. Awesome part is they're mostly about low bucks budget builds, step by step. Definitely recommend all his books

[@nerradnosnhoj5122]

Your channel is growing , you went from 20,000 to 31,300 as of August 16 2023 ..... Keep 'em coming !!!!!!! Thank you David and Andy

[@williamjones-xm6ng]

I have learned a lot from David through out the years. I remember the book I had read many years ago when I was still in high school on how to build small block horsepower on a budget. I have alot of respect for David. Growing up as child, my father owned an automotive shop and my father taught me so much about building race engines but he passed away a few years ago so I'm not able to ask him a question anymore when I am needing an answer on any given situation. I am able to find those answers to those situations through David's videos. I can't thank him enough for the knowledge! Knowledge is power and as my father always told me "never stop learning" and "speed costs money, how fast you want to go?" Keep on keeping on David Vizard and I will never stop learning from your knowledge passed along through all your videos. 👍🤙✌️

[@Lagrange1186]

I’m sorry to hear that your friend passed away. I look forward to you and DV teaming up on future videos. I learn a good amount from the both of you. Thanks for sharing this formula.

[@reevesautomotivefarm9614]

Thank you so much. spent years doing engine simulations to pick the cams for my 76 K20 tow vehicle and 69 Nova 440 hp 327. my numers came up very close to these recomendations. the truck 206/214 .461/483 at 38 deg overlap and pulls like a tractor. About to start putting the Nova motor together, Dart block, Diamond pistons, Jesel lifters, solid roller 224 deg and .525 lift. Car is my daily driver and comes in at 48 deg overlap. The 327 simulates at 1.4 ft-lb per inch at 110 seperation

[@davenorman8251]

I done the math on my 6ltr LS and I got 108.8 LSA..108 to 114 are common numbers for an LS cam 👍, using 108 as LSA I plugged in 50 for overlap and got 266 duration and 70 and got 286 thumbs up again IMO 👍👍 I'm runnin 232/234 (282/284) on a 110 currently on a Auto with 2500 converter..so I'm sayin the formula is a good thing.👍👍👍

[@UnityMotorSportsGarage]

Thanks Dave! Hopefully it can help folks.. DV is the man Andy

[@slick408]

Do you know what rpm your hp peaks at? I have an ls7 it revs to 7000 and the popular cams have wide lsa. Tighten the lsa it will have more overlap for the same duration possibly compromising idle and drivability

[@gordocarbo]

@@slick408 Carbs arent as sensitive to tight lsa, overlap Sequential like an LS is pretty sensitive thus less overlap keeps them happy.

[@matthewmiller2268]

​@@slick408you'll have to shorten the duration

[@BubbaAyers1969]

Always watching you and DV.. brings back memories from the late 80’s/early 90’s, all the testing we did to find the right combo, I hope this generation of builders listen to us old timers

[@gordocarbo]

THey dont...they want a chop, stage xx cam they know nothing about. Then refuse to regear, upgrade converter etc. They gotta learn their lesson that more isnt better and chop doesnt mean fast.

[@kevinclancy.]

Andy and David, I am soaking up all this great info and expertise. Already applying it to my 355 sbc, 108 LSA and the torque is awesome! Thanks for the great work

[@allanfranco4464]

THANK YOU FOR TEACHING GUYS LIKE MYSELF THAT IS SEARCHING FOR ANSWERS SO WE Can know what the hell where doing thanks i am still learning so much at 66years young

[@Anarchy-Is-Liberty]

I have very expensive simulation software that I use. I input every bit of data I have on my engine, then run through many different cam profiles until I find the one that works for what my intended purposes for that engine. So far, it's worked out very well. The one item I find that makes the biggest difference is head selection. You can't make a decision without knowing what your heads breath! Well, you can, but it may not work out so well for you. If you try running an 8000RPM cam on a set of stock heads, good luck making that work for you.

[@dukecraig2402]

Me to, I build Harley engine's for a living, I use that software also and sometimes I'll spend an entire evening going through cams until I find something that does what I want and it almost never is what the cam manufacturer's recommend for the application, but I wind up with better results than the other engine builders around my area, and no one can figure it out, as far as required flow I don't pay any attention to that until I get the results on that software I want and then I look at the required flow to get there then do what I have to do to get it, a big mistake is guy's will over flow heads thinking bigger is better but they'll lose that all important velocity because they don't understand how important it is, I have a math formula I used to determine the size of the ports I need to achieve that flow and don't exceed the size even the least bit, that's another thing about Harley's that make them easy is our ports are round so it's easy to do the math because it's just a simple diameter calculation, you don't need a degree in geometry to figure out the optimal port size, and we don't have push rod area's and water jackets to worry about breaking into. I'm all the time picking bolt in cams for performance applications and vice versa, one thing I have to deal with that car guys don't is the varying weights between different models of Harley's that use the same engine, some models weigh almost twice as much as another model with the same engine, that changes things more than people realize, and that's why the cam makers recommendations don't always work, I can hot rod a lighter bike and get away with keeping compression down so I don't get detonation pulling away from a stop but it still won't be a low end dog because it's lighter, then when the rev's go up it comes on the cam it feels like someone hit the back of the bike with a giant sledgehammer, I'll also shorten up the timing throw so it doesn't retard so much at an idle and that'll replace a lot of the lost bottom end, I'll shorten it up just to where it starts flirting with detonation then give it a couple more degrees of throw just to be safe. I also play around with gearing a lot to get what I want, Harley transmissions are easy to work with especially pre 04 Sportsters and fortunately through the aftermarket we've got a huge selection of ratios for the different gear positions to choose from, one of my Sportsters I put a close ratio 1st gear in that's actually for getting more dig out of the hole by lowering the final drive ratio (at the rear wheel), but I left that stock, as a result it'll exceed 65 MPH in first gear, when I tell people I have a Sportster that'll do that they say "It's impossible", I've won more 20 dollar bills off of people with that thing then you'd imagine, I didn't do it just for the the sake of it going over 65 MPH in first gear that's just a byproduct, I did it because we've got some very sharp curves in the mountains where I live and I'm into road racing, with that tall first gear I can hit a hairpin turn that's too sharp for 2nd gear and throw it into 1st and the power is exactly where I want it instead of the RPM's going through the roof causing my rear wheel to break traction and the engine being over revved, I'm right in the power and can slingshot out of the corner hard, since it's a solo bike I can get away with pulling out from a stop even on a steep hill because the weights down. People can never figure out how I do what I do because I think outside of the box and all they do is follow the manufacturers suggestions, I'm always using cams and gear ratios for what they're not intended for, that's why I get the kind of results I do and do it running on pump gas at that.

[@Garage95Engineering]

@@dukecraig2402 @Anarchy Is Freedom. If is not a secret, can you say what software do you use? Cheers.

[@tjed1071]

No matter how expensive a software is, still someone’s creation based on his assumptions to sell it and make money,… the question is… do you trust that software 100%? are you racing softwares or cars?

[@dukecraig2402]

@@tjed1071 That's not how the software works and until you learn how to use the information it gives you you're still in the dark, it's not like it says "Pick that cam instead of that one" or actually design a cam for you. It really doesn't do anything I can't do with a calculator and 20 to 30 minutes of my time, what it does is instantly crunch the numbers and shows you corrected compression, percentage of camshaft occupying the cylinder, lobe separation angle among other useful information and tells you which category of cam it is, ie street, hot street, street/strip and race only. They usually already have a cam library full of existing cams saving you the time from having to program in all the specs like intake and exhaust opening and closing in degrees, max lift etc etc, or you can design your own and see where all the values fall into without once again having to spend 20 to 30 minutes with a calculator figuring things out like corrected compression and everything else. Like any other tool if you don't know how to use it it's not going to do you any good, but if you do it give you more insight than someone who wets their finger and sticks it in the air saying "I've got years experience at this, yeeee hawwww". It's all about the math and how it crunches number's instantaneously speeding things up and giving you better insight, I love it because it saves me all kinds of time from having to make all the calculations myself.

[@ahoneyman]

The formula does use valve size as a variable. Head flow is important. Most aftermarket 2.02 heads flow extremely well. They flow so well that the engine may run out of cam or have valve float before it runs out of air. Sure, some freak may run 2.02 valves in a TBI swirl port head but that's rare and a bit silly.

[@jerryhablitzel3333]

I like the content. Both yours and David’s. So glad you’re ready and able to help David with his work. If I were you I’d try to sponge as much of his knowledge as my head could absorb.

[@andrewsteele2800]

Andy I love it when you and David work together, the best of both worlds in one. Would you be able to do a video on how to accurately work out dynamic compression? Some online calculators use @.050” duration and some use advertised. Surely it’s when the valve actually hits the seat that matters?

[@bradvall9416]

For the formula noted at 5:51, is the divided overlap based on 0.006" lift or 0.050" lift? For anyone interested, I found a similar question posted a month ago and Andy responded that it (the duration) is based on 0.006" lift.

[@bradgriffith4231]

"split" overlap is at the same place regardless of .006 or .050 being the lift number used. Split overlap is when the cam installed at 0*, not advanced or retarded. Most cams today are ground to be installed 4* or more advanced. Install using .050" to degree the cam is because .006 at the lifter is too small of a lift number to be accurate.

[@danielcadnum7214]

DV is the HP and Torque man! Thanks Dave for all the past, present and future awesome tire 🛞 burnouts. 😊

[@GregsAirplanesandAutomobiles]

Another great video, and of course I went right over and subscribed to DV's new channel. I have read his books and been applying his lessons for decades and with great results.

[@MH-53E]

I really enjoy this technical gold and best of all learn from you guys. Stick together guys, it makes you both better. Both of you have different skills that work good together... Thanks for doing this fellows.

[@fastekibeast9486]

I recently got build up my new Pontiac engine where I used DVs 128 formula. I also used his overlap chart, the very same you showed us all. It feels and sounds pretty healthy and crisp. So, I think the 128 formula work also with Pontiac engines. I also bought the Progression Ignition distributor in it cause YOU encouraged me. Keep up the good work and let the know-how grow!!

[@kellynestegard5208]

So what was your LSA? For my 400, I get 102 degrees LSA. This seems really tight. Most street Ponchos are running 110-112.

[@fastekibeast9486]

@@kellynestegard5208 106* LSA

[@TheMrmmkkpro]

Good info. I'm working on an old school build, a 1972 455H.O, 30 over, trw L2394 pistons, 7f6 heads. The cam in it now is 110 as far as I remember. Can't wait to use DVs formula on my build👍👍🏁🏁

[@robtdougherty]

@@kellynestegard5208 - Curious too as i just ran a quick calc using 128 for my BB Olds and it came up with 103!! haha

[@deankay4434]

I am seeing this for the first time as a retired dealer repair tech. I understand that software is complicated but I wish this small part could be used on a fictional engine in a brief explanation. I guess I can search for it, wait for that video or go to David V's channel that I subscribed to. I just want to understand but it takes one part at a time to build an entire understanding. Thanks.

[@tommyridolfi9261]

Yes Andy I’m a 68 year old man building a 1970 340 Cuda. At this age I got the street car bug again and I’m lost as far as a cam. Thank you for your videos.

[@UnityMotorSportsGarage]

Tommy that is awesome! Thank you for watching and for the kind words.. you can email me at [e-mail] about the cam

[@billcat1840]

I'm going to use this formula for my little 318 Magnum..the more I reduce the factory restrictions, the stronger this little thing runs. I figure out little engines are brothers so I hope it works out for you too.

[@antilaw9911]

Call Hughes engines. They're in Illinois. I believe it's Elgin Illinois. They are Mopar specific only. They make "Real Chrysler cams". That take advantage of the .904 tappet diameter. Not many old typical Chevrolet specs put on Chrysler cam blanks.

[@theshed8802]

Great video Andy. I purchased DV's Torque Master and IOP software. Both are great programs. Like all new software it took a little to get my head around them, but I would highly recommend them to other viewers. As well as DV's books. Regards Greg

[@UnityMotorSportsGarage]

Thanks for the input! I feel exactly the same.. the 128 formula is just a snap shot of what the Torquemaster program actually does.. Thanks for watching, Andy

[@WellOiledGarage]

What you're saying makes a lot of sense. That formula for a 6.0 LS spits out 102.6° and one of the best area under the curve cams on the market the BTR Truck Norris has a 107° LSA which is one of the tightest on the market for an LS. A lot of people including myself in the past fall victim to buying too big of a cam that has a domino effect leading to less than desired results

[@anthonysantiago1999]

I would have been that guy who goes with the Information the Camshaft manufacturer would either recommend or advertise. Fantastic information on Camshafts " The Brain of an Engine" as I like to call it.. Great Stuff Brother!!

[@antilaw9911]

If you have to call a cam company for recommendations they figure your not experienced and will sell you a baby cam

[@nobodyspecial5026]

I bought and read DV’s books back in the late 1980s and the information in them was so far ahead of it’s time. I had just graduated as a mechanical engineer and it really opened my mind’s eye on how to assess and view such things. Which I benefited for a lifetime with. I trust his methods completely and without question. So this wasn’t clear in the video; when doing the intake lobe duration calculation is the result for the advertised or 0.050” value? Because I’m trying to assess a SBF 347 stroker build on the Powernation channel for a sleeper Granada build. They chose a 110° LSA when the SBF 127 formula suggests 104°. Which on the dyno it only made 1.277 lb-ft/ci using AFR Renegade 205 heads w/Jesel 1.6 shaft rollers, Vic Jr intake, 950 cfm 4-bbl, and Comp Cams High-Torque 406 MechRoller cam; 280/292 adv. duration, 110°LSA, 4.5° advanced, 0.650 lift, 46° overlap (by my calcs). Which at 1.4x would yield about a 10% increase in peak torque. It would be interesting to see a projection on what the program might suggest the outputs to be using the preferred 104° LSA instead. .

[@rennypizarro4432]

My first SBF hot rod build back in 1981 made 1.17ftlbs/cuin. I am sure had we used the correct 110LSA instead of the company suggested 112LSA we would have had seen better results. Prof Vizard teachings have yet to fail me. I dont know why so many regard them with suspicion. Thank you for stepping in Andy. Continue the great work. Blessings to you and Prof DV.

[@superkillr]

He's not a professor of anything.

[@edsmachine93]

Thanks Andy and thank you DV. I appreciate all of your help. Take care, Ed.

[@UnityMotorSportsGarage]

Thanks for watching Ed! hope all is well your way.. Anytime, Andy

[@captainwhiplash]

Andy guys like us have to have guys like David or this home shop and teaching our children will disappear brother. I’d give almost anything in the world to stills have my ole mentor. But I’ll settle for you and David. Thanks for all you guys do

[@antilaw9911]

Called Hughes engines in Illinois years back for a cam recommendation for my 440 build. Was not disappointed! He asked me if I'm going to drive it around on streets but also like to burn the tires off and have fun? And said, it's a moderate cam but 440 is big cubes. I got the Hughes "Real Mopar cam" BL232. Flat hydraulic. 232@50 110. Had very noticeable idle but not rough at all. Ran super great with 10" 3000 stall and 3.91. Matching valve springs etc. Crane gold 1.6 race rockers. Engine would just keep pulling hard. 👍

[@shoominati23]

DV , in one of his books (I can't remember which one, It's been a while - give me a break!) published a carburetor venturi to cylinder size graph. And after trying 4 pairs of carbs on a Suzuki 1100cc GSXR, I told my friend he had nothing to lose by at least trying 'what the book' said , so the 32mm carbs ended up being spot on for the bike to hit peak power at 11000rpm or so , and it was only after going through 20 carbs (4 cylinder bike don't forget) lol .. I don;t know what type of carb it was, motorbike carb, flatsides, pumper / non, etc that's a whole other rabbithole in itself

[@hotrodray6802]

DV is the #1 engine engineer in the WORLD. Damn good chassis engineer too. 👍👍👍😎

[@mcarnet]

Forgive my ignorance, but what about the exhaust duration? Is there a seperate formula for that? Fantastic information, learning a ton!

[@StainlessTIG2]

I’ve heard of the 128 but never used the formula. I’m at the middle of number four. I’m running a mild mechanical flat tappet in my 0.060 over Windsor. Stock crank with forged rods and pistons. This engine has way exceeded my expectations. Of course the reason why is circled on the valve covers.

[@chrissandvoss5017]

Terrific videos Andy (and David). I love your style and humility in passing on fantastic information. I have a Ford 300 six that shares the SBC 4"bore with a 1.94/1.60 valve combo. It isn't a flow through head but I'm wondering if the 128 formula would potentially work with the Ford Big Six. Thanks in advance!

[@jakal104]

Years ago, there WAS a very limited run of aftermarket aluminum cross-flow heads for the 300cid. It used the standard cam in block and had a funky shaft arrangement under the unique valve cover to actuate the valves. I don't remember what they used for headers. I wanted one but couldn't afford it. 😒 Hindsight, I should have bought one (or two)... to this day, I still think the 300 could be a killer hot rod engine with a modern head design.

[@brucearterbury1856]

Great question! I’m building a 1969 292 bore and stroke 3.875 by 4.125 Chevy straight upgraded to 1.94 valves 6 for my 56 GMC. I live at 6,500 feet elevation and my pickup is going to be carrying a slide-in camper up the passes from here. So, duration for towing and I am wondering what corrections are required for the 292?

[@chrissandvoss5017]

My first engine, at age 10 was a 292. I’ve been in love with the straight six since. High altitude means more compression is possible. My Schneider cam 142F is a solid tappet 242@.050 cam but with a 112 LSA for a turbo application. I have yet to assemble it though, so no feedback at the moment. I was tempted to order a cam at 106 LSA given the parameters of the formula, hence the question

[@brracing7861]

Played around with the DV 128 Formula today again. Reading Comments for 132 substitute for Big Chevy, I worked out my Pontiac V8s 400 and 455. Came up with LCA that I use that delivered best Torque and Hp for myself many times. I rounded up. Substituted 133 and it's dead nuts on for My Pontiac V8s.

[@darrellsomers5427]

So what's the cam specs on that poncho ?

[@brracing7861]

@@darrellsomers5427 kzbin.info/www/bejne/rHm1haRmbZamaNU Just a little cam by todays Racing Standards. This cam is Similar to the Pontiac Ram Air 4. Single pattern. .530 inch lift with Factory NOS RAIV 1.65:1 Rockers. Revised LCA & ICA. True 455 cubic inches 1976 Pontiac 455. 1971 GTO #66 Heads I ported myself to 270 cfm @ 28 inches intake and 202 cfm Exhaust @ 28 inches. Static compression ratio just 8.4:1 sane as SD455 Trans Am used. 1085 cfm Annular Booster Double pumper Carburetor Custom built for me to my Specs my BLP Racing Bo Laws. Racing again in 2023 #nonamenationals event with my 1970-1/2 Trans Am RAIV 4-speed and other Events to Win Money $$$$$. Sorry Can't disclose exact Cam Events. If Build you a Pontiac V8 or other Brand Engine Be Happy disclose IVO, IVC, EVO, EVC @.050.

[@madisonbusman7688]

Awesome video here. I'll be applying this for my next build. Thank you for sharing your knowledge guys!

[@TonysHotRodGarage]

Great video as usual. I'm glad to hear that you and DV will be creating more content together. This is going to be great!👍

[@UnityMotorSportsGarage]

Thanks Brother! Im looking forward to it. Im at his house a couple times a week anyways.. might as well do videos on what we have going on! Andy

[@UnityMotorSportsGarage]

@@N-Lee LSA is the term commonly used in the US in other countries it is often referred to LCA...

[@First_______]

@@UnityMotorSportsGarage He's right and you won't admit you screw'd up. LCA and LSA aren't the same. You probably lie that you know David Vizard too. I'll encourage people to stay away from your channel.

[@UnityMotorSportsGarage]

@@First_______ well I can tell you haven't watched the video! David Vizard is in the Video with me.. what says you now?

[@First_______]

@@UnityMotorSportsGarage You're right I didn't watch the Video. I saw you didn't know the difference between LSA and LCA and didn't bother to explain it, your video is misinformation

[@1985oilers]

I enjoy your videos. I have wondered for a long time about something that I believe to be true. I would love to see a comparison between identical cams with different lobe separation angles. However, I would like them advanced so that the intake lobe centreline on all the cams are the same. Example: a 114 lsa advanced 8 degrees, vs a 110 lsa advanced 4 degrees, vs a 106 lsa straight up. This only moves around the exhaust centreline angles. Test them all with open headers and with a slightly restrictive typical street exhaust system. With an exhaust system in place I find that wide lsa cams run advanced work better. Move only the exhaust centreline and see what the results are. Thanks

[@allenhay4811]

Thank You David for all the Knowledge and Wisdom You share. It'll Truly Help Me in the Very near Future. And Thank You Andy, for if it wasn't for You, None of Us would even know David.✌️

[@jtdyalEngineer]

Dude that is so weird, on Tuesday I asked in a text "how do you calculate the RPM of peak torque and peak power based on camshaft, bore and stroke. The Thursday you published this info. Awesome thanks

[@UnityMotorSportsGarage]

I'm glad you enjoyed it Andy

[@markcarter78]

This video is by far the best you and DV have done yet!!! Thanks a ton. I will never buy a camshaft from comp ever again. I am also not happy with howards. I have the TMC program and my engine wants, needs a 106 LCA. I haven’t found anyone who will grind it. Howards said all they can do is 108. It’s frustrating because when you give them your specks they laugh. I know you guys are right i am convinced. Please give me a place to buy a custom grind. I also have a big FE ford engine that needs a cam. Thanks again you guys are the best.

[@UnityMotorSportsGarage]

Thanks Mark! It depends on the cam core itself if they can grind on a 106. Im glad you enjoyed it! Andy

[@bcbloc02]

Try camcraft I have never had a problem getting them to grind anything I ask for.

[@markcarter78]

@@bcbloc02 thanks i will do that monday. Dont you just love these guys

[@garyhosier4765]

God bless you guys for supporting each other and us. Take care of each other.

[@JustMoparJoe]

Awesome video and Congratulations on the 20,000! Looking forward to to the next installment!

[@UnityMotorSportsGarage]

Thanks Brother! I'm glad you enjoyed it Andy

[@laiky71]

Please discuss how the tighter/wider LSA affects drivability and idle quality. Can i pull OD from 1200 RPM with a tight LSA? If i can. i may need to buy a new cam!

[@jbrennan123]

Good Video Andy! I'm looking to spec a flat tappet billet camshaft for my Ford FE and I think that this formula will certainly come in handy.

[@GregHuston]

I ran the 128 formula for a small block Oldsmobile I’m building. I come up with a 108 LSA, oddly enough nobody makes a lower RPM (street) off the shelf cam with less than 110 LSA. I have 272/280 Lunati voodoo hyd roller from a 403 but it’s on a 112! I’m thinking about getting a custom grind but I’m curious why all the cam makers go with a wider LSA for their off the shelf cams for ~1800-6000RPM cams?

[@richdouche8253]

I suspect they ad those cams to the general public to minimize complaints and product returns based on "bad" idle quality. Spread the lobes and the cams don't come back.... Even if they're making 20tq/20hp less throughout the curve.

[@87PontiacGP]

Great content, love both your, and DV's channel. Question I have: Would this formula work with Buick engines? No special difference for this formula? I assume not, but always good to double check. Great content, the both of you!

[@MrRandy3504]

Set up a website with a cam calculator on it like hp or et calculators cause that is far too much math for me and i always have issues getting a correct cam

[@bryce1916]

I agree with what you say from personal experience . I like how you pointed out that wider lsa on a ls isn"t always correct , I went from a 116 lsa to a 112 and it gave me more torque at a lower Rpm and this gave me more of where I wanted the power as I don't race .

[@johnnyatkins9097]

I like your videos and DV’s as well. This is stuff I have in his books but it’s nice hearing it explained. It help give you a better understanding of the information. Thanks.

[@rustonwheels3064]

Great video! Thanks to both of you guys! giving out and sharing these valuable information for orientation is so awesome! is there a way to align this equation with changes in compression points?

[@jimfryar1]

Vizard is an icon!! My question is, how do you know where the intake valve centerline needs to be (degrees) thanks

[@JohnDoesItAll]

Thank you. What if I'm running 13.5:1 compression? I've always focused more on torque than hp for my street engines. My Camaro ran mid 12's with a sbc 400 capped up with a Jegs R/V - towing cam and was my daily driver for years. Pick the cam first and match everything else to the cam.

[@shawntailor5485]

Dave's a genius much appreciated.!

[@UnityMotorSportsGarage]

Yes he is Shawn! Andy

[@shawntailor5485]

@@UnityMotorSportsGarage I have a book with the DV street ram in it from 35 years ago or so ,got a wiend Stealth intake on my Elky ,but never got the DV street ram done .I actually heard about it in the army 1979 from another soldier . I met a man named Ron Shmetzler in 70s that already heard of Dave .Ron sold offenhouser the patent for the hidden nitrous manifold ,owed the high rev store by my grandma's house .

[@sr20dett1000]

On a stock ls1 with 799 head compression 10.5 the formula is getting 108. I saw Richard Holdener Dyno with 108 112 117 I think the 108 made more power everywhere.

[@UnityMotorSportsGarage]

It did! Andy

[@billsmopars4927]

Good video. Between you and DV there is always something to be learned on your videos.

[@UnityMotorSportsGarage]

Thanks Bill! we are glad you enjoy them and get something from them.. Andy

[@UnityMotorSportsGarage]

@@Roxx______________ LCA and LSA are the same... You are referring to Intake centerline!

[@UnityMotorSportsGarage]

@@ViewThis. we will let DV settle it.. how's that

[@UnityMotorSportsGarage]

He is in the video with me! In fact I'm in his best selling Cylinder head book and have worked with him for nearly 20 years... Have a nice night

[@rickolson9075]

Ok the chevy 372CI early 262-400 indicated 107LC. With 50 OL for street it came to 280 duration is that advertised or @0.050" That is really really big for the street 280 @ .050" Now with vacuum breaks and a automatic that 280 @ 0.004" would be good. Some heads flow better than others the over lap should be altered lower if the heads flow really well. I hope you can talk about more exhaust duration and lift to maintain or fix the above 91% of exhaust to intake flows dynamics, plus extend rpm range. Lastly, intake lobe center; it's mostlikely easier for me to find where the intake closes and keep it about 35 to 40 decrees to keep the dynamic compression ratio up and set the intake lobe center that way. You might have a better way to figure that out. Because initial timing messes with rpm range as well. I like your channel

[@bobgyetvai9444]

Im having some questions about this Terry . The engine is a 4.8 ls with 10.5 to 1 . Ported 862s with 1.89/ 1.55 s flowing 225 @400 and 250 @ .550 lift @ 208 cc . Im considering fillng in the bottom of the port to short turn apex height and the Truck plastic F.I. runner to increase velocity with no flow loss . My lsa figures to be on a 110 useing the formula . Ive found a cam that the dynamic compression ratio of 8 .037 is realized but with 45 deg overlap . (553/553 , 208/214 @.050 , 110 lsa Camonics Titan stage 1 ). However wallace racing calculations says the compression will only be 165 psi with this cam . Im looking to crowd 200 psi like you and David have said . What am i doing wrong ?? I desire a outcome of 1.4 ft lb per cube = 410 ft lbs ?? Stock on a engine dyno and tuned its said they make about 340 ft.lbs . I suppose i should be looking at a bit different cam ?? Please help with the details of how we can accomplish these figures . For me this is for a Silverado pu with 3.42 gearing , 31 inch tires , a stock torque convertor , and stock exhaust with no computer tuning Ive achieved 32hwy/27 city milage consistantly Stock even loaded so far . As delivered economy was 20 hwy/14 city . Ive come a long way without a tune or going internal with stock exhaust . The Preformance with Economy is Important . This new engine with the features listed i hope to do great things with your help . Ive already built several preformance engines with tight LSAs and am a Believer in the Power !!! But i have no experiance figureing out my goals with 293 cu in and being milder with barely a lope plus working with 1800 rpm stall stock 5.3/6.0 convertor and the same 1800 rpm on the hwy at 70 . I tow often . Thank you .

[@DDDD-of3hv]

i'm running a 106lsa now and really wish i had went tighter, next time i will try to go to 102 the formula says 103 is what i would need i love that how snappy the torque is now and of course the idle it's therapuetic there's other factors that can determine your lsa as well.... sims/dynos/real time are all going to show different things, so use them as a tool to help you determine it is hard to find a manufaturer that has real tight lsa's

[@gabrieldimarco9646]

Hi Andy, intake valve duration needed is based on .050" valve lift or .015" tappet lift?

[@stevecotter4073]

The factory 1968 340 cam for 4 speed cars is almost the same as David Vizard's formula comes out to. Great video

[@ZacLowing]

275hp out of a 340 is not a ringing endorsement. Yeef

[@danielslocum7169]

@@ZacLowing it was under rated for lower insurance rates; actual hp was 315-320. its performance on the streets is legendary.

[@3800S1]

I just ran both formulas for a cam I already bought that is the very same used in the open wheel formula series here in Aus for the Buick v6 and is a pretty proven cam as millions was spend developing the series and the vehicles. And the duration came out exactly 303 as per the cam report print out, and the LSA formula spat out 107.8 ish, the actual cam is 106.3 so looks like I have a winner! The specs for the engine is planned to have between 10.5 and low 11s for the comp and to run on premium 98 ron. Playing with the figures on the formula, it seems the ratio from valve size (it's small in the Buick) to the cylinder volume is the main thing that changes the LSA, small valve or big engine= tight LSA and I already interfered that from experience as these engines like a tight LSA and higher overlap. The factory did it throughout the 80s and early 90s, then with the 3800 II it all went to crap sharing the similar design architecture as the LS v8, physically as well as cam specs, wide LSA etc... And they are just a disappointment compared to the older engines. When I built my first mild hot engine in 2015/2016. I ran my dynosim 5 software though the ringer and time and time again to try eliminate nonsense results, it resulted in a retarded cam and tight LSA, so I decided to go with this. And yes it worked! 109 LSA on a 212 adv cam, mild but I still got 180Kw at the crank at 5500 rpm. The adv/ret maybe not totally right, but it did make power higher up like I wanted, but in hindsight, I would have designed a much larger cam as it still ran like stock down low and I would have happy sacrificed more for overall power. Just recently, I finally confirmed it once and for all. The crow cams stage 3, popular cam but also suspect made the Buick v6 a reputation of being an engine not worth touching for mods, I got given a car to tune with one of these cams as no tuner or mechanic could even get it running. Well I'll tell you, this 207/210 cam with 113 LSA was a nightmare to get running, it exhibited all the classic cold start and idle fuelling issues, over fueling from throttle crack and transients of a bad combo. I spent a whole week reworking the entire OEM side of this and got it to start and run great in the end, but it was unresponsive, gutless for what was very similar to my cam except one thing, the wide LSA.

[@slicepizza3263]

What number is used on a hemi? 133? Does the .91 have anything to do with the throat percentage?

[@Bbbbad724]

I misspoke on my 394 ci FE. I read David’s writings. I used the 128 because the engine breathes very well. I made a company grind me a 107 LSA cam straight up 107 intake 107exhaust 107 LSA I got 512 ft lbs and 503 hp with 54 degrees of overlap. I ran a 69 RA 400 GTO with a 65 Galaxie and it blew him in the weeds. That 394 has been to 7000 rpm’s and it is loud! It sounds like a hot 428SCJ that ran in C/S. I can’t find my other post. But people get sick riding in it. DV is the man. Everyone told me it would be a turd because it wasn’t a dual pattern. Why run less duration on the intake when all exhaust just wants out. FEs had the same exhaust port from LR to Tp.

[@JACB006]

Where is David Vizards cam program or it’s output available?

[@UnityMotorSportsGarage]

He has it available to purchase but with Marvin's passing we are having to come up with a new plan... The Programs are distributed by Stan Weiss Andy

[@The340king]

I have used a combination of previous experience, Engine Jr. parameters, and further refinement using Engine Analyzer Pro. These are heads up circle track race engines. They have won many races using these techniques. I was once challenged to select a camshaft for a 383 Chevy that would allow a full bodied El Camino to run 11.50’s on pump gas running less than 6,200 rpm. It took quite a bit of analysis to develop the proper cam. In the end we were successful with runs at 11.53 in the quarter mile on 91 octane pump gas. He won his bet.

[@ghostmeplz3984]

Using desktop dyno I got 1.52lb ft on a 302 build (458lb ft at 5500rpm) with a dynamic compression of 7.93:1. I guess I am heading in the right direction?

[@outfitsgarage88]

Great information. I'm still trying to learn what all these numbers means. A brief video on LSA, / OVERLAP / LIFT AND DURATION. Would be helpful. Nothing really long going into to much detail on each Would help a lot. I'm sure DV has already made one

[@brracing7861]

The DV 128 LCA Formula is interesting. One Old Time Mechanical Engineer introduced us to the Formula a small group of us back in 2011 on his closed Forum. LS Was just getting Hot. Most of us into Old School SBC, Big Chevy, Ford 302 , Pontiac V8. We usually came up with very Tight LCA Profiles called for. Most of the Old Timers wanted to Street drive cruise with Overdrive at 70 mph steady. Younger guys wanted To Street Race like myself . We mostly applied the DV 128 Forumula for 454 & 496 stroker BBC. Then EFI and Boost psi wanted wide LCA preferred for ease and 100% stable intake manifold Vacuum so the MAP Sensor wouldn't go berserk. Back then I was on The Corvette Forums and all Generation EFI Corvette owners stated it was impossible to proper tune a Radical Lopey Camshaft Tight LCA with burning chips or Hp Tuners used. Only if you used a dedicated stand alone EFI Alpha Numeric Tuning software that is only good typical for WOT.

[@chevyrc3623]

BBC and Cleveland uses 132 not 128 like SBC and Mopar engines

[@plumcrazy588]

Like I asked on DV's channel, Is there a formula adjustment to use if you aren't using 10.5 compression ratio?

[@andysteele4056]

If you are down below 8:1 you might subtract a degree from your LSA and over 12.5 might add a degree, but you wouldn't have to. Higher compression will push and pull on the air harder near TDC and act like a little more cid.

[@jeffwooton7138]

DV's books have that precise adjustment information. I know I've seen it in there. I wish I could remember. Guess I need to read it again

[@romantijerina5364]

@@jeffwooton7138 exactly

[@dirtyburd71]

@@andysteele4056 hi! So to clarify what you have said, lower compression TENDS to want a tighter LSA and higher compression TENDS to want wider LSA? Thanks! This stuff is so interesting and puts "common knowledge" into perspective on cam choice - "bigger is better" which has bitten a few of us in the past! 😉

[@Robbb8227]

@@jeffwooton7138 do you know which book DV has many

[@ericfrontczak8016]

Ford man how do I figure out what kind of cam for a 300 ford 6 towing farm use? Trying to soak this in but it takes time

[@mattsautorepair484]

I'm curious why the factory seemed to favor 113-115 lsa, idle quality for sure but is there an effect on fuel mileage?

[@Comet-hn3gm]

I subscribed to DV new site a while back, and your site months ago, maybe a year + I have used DV's information and my own experience for the last 15 years or so. In most cases I spec my own cams. I use Bulletcams and Jones cams in most applications. Getting ready to install a Jones cam in my 408w next month. You might even be able to tell what it's in. I like the T shirt.

[@pete540Z]

Thanks, Andy. I subbed to DV's "new" channel a couple of days ago, and also purchased the TorqueMaster cam program.

[@jeffwooton7138]

Just my 2 cents. Having read all the comments, what folks are forgetting is, this formula is for a SBC, 10.5:1, with good heads, on a carb'd engine. He states that specifically in his book. The "128" gets adjusted based on CI, and head type. This is what I understand from reading this and thinking on it for years. I'm trying to equate this to a modern LS, with FI. I'm still working on it in my head, so I don't have any answers yet. Still hoping to see DV's testing results with FI. From my understanding, the FI introduces a different twist on the determined LSA, due to available plenum volume, and the need for vacuum for the brakes. I've got hydro assist brakes, so no worries there. But, the LS heads all have a different valve angle (15*), and way better port volume and energy than any old SBC head ever made. I believe one must consider all of that as well. DV will get us the info soon, I'm sure of it. In the mean time, my suggestion would be to use Jones, or Straub, Brian Tooley, or Kip over at Cammotion for LS stuff. Holdener does good work too, I'm just not 100% in agreement with his testing methods yet.

[@hotrodray6802]

DV's program is specific. Here AW and DV are giving more specific information to the general community to make their results much better, but maybe not absolutely perfect, without dyno looping the cam timing, as DV emphasizes. JMO 😎

[@jeffwooton7138]

One other point on LS engines....Why the duration split? I just can't figure why almost every single cam has a 6* duration split. I get that the intake port is so much better. But if one does the flow comparison, intake to exhaust, the percent let down on the exhaust is within 1 to 2% of the SBC. Why the need for so much exhaust duration? I've not gotten a solid answer yet. Or one that I can understand. Again, I'm after all the torque I can get. BTR has their torque cam. It's smallish, and is a single pattern cam. Would that not work using more duration, up to a certain point? My guess is my wallet is what will help me find out.

[@charlesgreathouse7376]

Thanks David and Andy.

[@TheGearheadLounge]

Thank you for this video! I learned a ton! Subscribes to DV's new channel. I met him back in the 80's at Westech! At the time, he was developing an intake valve that had a spring loaded mini-valve, and would open slightly to allow a small jet of fuel before the valve opened completely. It was a pretty interesting concept!

[@ronaldleist7808]

What about big block Mopar What should I use for my 440?

[@bcbloc02]

I find intake runner length has a lot bigger impact on torque production than the cam LSA but that is only somewhat speculation as only once have I ever done a dyno test where everything was the same except changed from a 105 to a 102LSA on everything else the same and in that case it lost 20hp but that was an engine making 1200hp.

[@hotrodray6802]

Did you run multiple cam timing loops or just guess?

[@bcbloc02]

@@hotrodray6802 Both cams were tested from 95-110 IC in 2.5deg increments

[@jakal104]

Well.... that 1180hp engine is just plain junk! I'll swing by and pick it up, get it off your hands, say... next week. What's the addy? LOL 102 is really tight for pump gas. Was this a stroked BBC?

[@bcbloc02]

@@jakal104 it was a turbo diesel

[@vinnylc]

I think a big reason the 112+ LSA number have become common place is the tuning aspect. Less than that and it and the computer will freak out and see a rough idle as a misfire and try to correct it to death. Carbs dont care and can run a 106 LSA without trouble. So if you want to run a low LSA on an LS then you need to be ok with a high idle (not good for street) or run the wider LSA so its become a staple in the grind for LSs for the wrong reason. Long story short the Fuel Injection tuning aspect is the culprit for this myth.

[@fabianruiz4796]

What camshaft you recommend for GMC 06 4.3 L V6 thanks good video

[@bdugle1]

Is the 128 number (and the .91 factor) good (close) for an LS with 10.0:1 compression? Is there any variation for LS engines running rectangular port heads vs cathedral ports? Before porting there’s a vast difference in intake flow vs displacement (also a big intake valve size difference), which would seem to affect the LSA desired. I haven’t done thousands of dyno tests, so maybe that “feeling” is wrong! BTW, I followed DV to the new channel immediately.

[@davidreed6070]

You use the valve diameter, it works out fine

[@72chevelle156]

how could DV loose subs? He is the ultimate go to for engine knowledge.

[@bcbloc02]

His old channel was under his partner Marvins login, when Marvin died he lost access so essentially the old channel just floats out there uncontrolled these days. DV had to go to his own channel to regain access so he can post and edit materials.

[@rogerstill719]

I really like your videos and Mr. Vizards videos. I am so happy to see he is doing well. I don't talk to many people anymore... they know too much

[@vestal2245]

When you complete the equation for intake duration, is that number for advertised, @.006, @.050 ? I did it on an engine and ended up with 303. But I don't know where to go from there.

[@jodypaul2695]

I would love to know how the valve angle affects this formula and how to adjust the formula to the valve angle of the heads. Thanks.

[@jwd1112]

I read David’s How to Build Horsepower book 8-10 years ago and it is excellent, it taught me a lot. When working on the formula, the I take duration number is advertised duration (.005), correct? What formula do you use to get the exhaust number?

[@colinhoppes1167]

What would a 9to1 boat engine be happy with also keeping in mind reversion creates multiple issues with wet exhaust bbc 502 ported the heads watching David's video and followed very closely also preferred not to spin beyond 5500rpm

[@dennisrobinson8008]

So a set of heads on a 350 cubic inch v8 flow: .300" 185 cfm .400" 210cfm .500" 260cfm .600" 265 cfm You have two camshafts each with 220 degrees @ .050" and 112lsa, one has .425" lift and the other has .610" lift. How much more power will the camshaft make that lifts to a point where it makes 50+ cfm more? I know if i took a set of heads that maxed out at 210cfm on that project and swapped them for a set of heads that flow 260cfm, that power will be made, alot of it in the same combo, 30,40,50HP perhaps.

[@remybrouwer8700]

What is it for 4 valve per cylinder, 4 cylinder engine

[@davehaas6830]

Intake duration question with the formula your using is that number advertised it @.020 or @.050 Thanks Andy you guys make a great team !!

[@UnityMotorSportsGarage]

Dave, it's based off .006" advertised duration Thanks for the kind words and for watching Andy

[@ryno6101]

I’m on board with the formula, so 408/8/2.25x.91= 20.62 , 128 - 20.62 = 107.37. Which the stroke is 3.766 and it could be a small block but it’s a big block Chevy. So if I subtract 132 it comes out 111.3 . I’m guessing I’d be better off at 107 because such small a motor?

[@johnnyhonda7576]

I’m building a 393 Cleveland with 4V quench chamber heads. I called Bullet and got a Rep that raced Cleveland’s in the 1970s. He told me the profile to get from them for my 450 Hp application. So I feel comfortable with his recommendation based on experience. So should I be apprehensive? I thought Bullet was one of the best? My engine isn’t built yet. And fled to hear your a Ford Man!!

[@slicepizza3263]

Andy, What equation/formula did you use to pick your camshaft for your hemi head motor? 127, 128, 132, 133, or something else? Please and thanks

[@hughjass7025]

Thanks for sharing this. Does using the formula to find intake duration give you advertised duration or the duration at .050 lift? The numbers I was getting for a street/strip 350 seemed too large to be duration at .050

[@manitoublack]

Second comment. This formula is really useful for twin cam engines, where you can use this formula to grind the '0' position. then with adjustable gears play around a little to see what's best. Gives a great starting point.

[@hotrodray6802]

DV emphatically states the dyno testing for the proper installed angle is ABSOLUTELY NECESSARY

[@hotrodray6802]

🔔😎 Is the overlap estimator based on SEAT timing ?? Thanks AW & DV. 👍😎 Updated with a more detailed post.

[@hotrodray6802]

.050 for overlap.

[@jameswhitesell3076]

Does this apply to gem3 hemis, or do you need to imput a different number? Also, what about split duration cams?

[@brucejones7389]

I have a stock 429 Thunderjet in my 69 thunderbird and I was wondering how to apply DV's formula to my engine for a new cam recommendation

[@UnityMotorSportsGarage]

Bruce, I sent you a message on FB. Hope you have a Merry Christmas Andy

[@scottosborne8735]

Overlap specifications: are these values at 0.050", or at advertised timing events?

[@cuda6496]

Where can I get the David Vizard's computer program?

[@UnityMotorSportsGarage]

I think Stan Weiss offers the program. Andy

[@cuda6496]

@@UnityMotorSportsGarage thank you !!!

[@UnityMotorSportsGarage]

Here you go www.magneticlynx.com/DV/

[@cuda6496]

Thank you very much !!! 🤘💀🤘

[@williamfowler8028]

I understand just glad to know there are a few ford guys out there. Love your truck and the video on the c-4 you did a while back.